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(No Model.) 3Shets-Sh6et 1..

A. PQYARROW.

WATER TUBE BOILER.

.WITNESS v INVENTOR fgw W am 7 fi I A ATTORNEY (No Model.) 3Sheets-Sheet 2.

' A. F. YARROW.

WATER TUBE BOILER.

No. 472,777. Patented Apr. 12, 1892;

WITNESSESC v I INVENTUR 620W v i Q ATTORNEY (No m dei. 3 sheets-sh en s.

A. P. RROW.

v WATER BE BOILER. No. 472,777. Patented Apr 12, 1892.

WITNESSES manna! UNITED STATES PATENT OFFICE.

ALFRED F. YARROV, OF LONDON, ENGLAND, ASSIGNOR TO HORACE SEE,

- OF NEW YORK, N. Y.

WATER-TUBE BOILER SPECIFICATION forming part of Letters Patent No.472.777, dated April 12, 1892.

Application filed August 8, 1891. Seriel No. 402,073. (No model.)Patented in England November 11, 1889, No. 17,958.

To all whom it may concern.-

Be it known that I, ALFRED FERNANDEZ YARROW, of Isle of Dogs Poplar,London, in the county of Middlesex, in the Kingdom of Great Britain,have invented a new and useful Improvement in ater-Tube Boilers, (forwhich Letters Patent of Great Britain, No. 17,958, were issued to me,dated November 11, 1889,) which invention or improvementis fully setforth and illustrated in the following specification and accompanyingdrawings.

The object of this invention is to provide a simple and' strong boilerof comparatively light construction, the ends of whose tubes shall beeasily accessible for the cleaning, repair, or renewal of the tubes.

The invention will first be described in detail and then particularlyset forth in the claims.

In the accompanying drawings, Figure 1 shows a part-end elevation andpart crosssection of a boiler embodying my invention, set within thetransverse contour or outlines of a boat or vessel. Fig. 2 illustratesin longitudinal section the parts shown in Fig.1.. Fig. 3 is a viewsimilar to that shown in Fig. 1, but having the tubes differently set inthe tube-sheets. Fig. at shows in cross-section a modified form ofconstruction in which there are two upper steam and water chambersconnected by crossed tubes to two similar lower steam and waterchambers. Fig. 5 illustrates in end elevation the modification shown inFig. 4:.

In said figures the several parts are indicated by reference-letters,like letters indicating like parts.

Referring to Figs. 1, 2, and 3, the letter A indicates an uppercylindrical water and steam chamber formed in halves secured together byflanges A. Two bottom waterchambers B B are connected to the chamber Aby the water-tubes O. The chambers B are constructed each of asemi-cylindrical part B, closed by a flat cover B bolted to flanges onthe part B and having holes into which are screwed or otherwise fixedthe lower ends of the tubes 0, the upper ends of which are screwed orotherwise fixed in holes formed in the chamber A. The furnace D issituated between the bottom chambers B, the flames or gases ofcombustion being caused to pass transversely between the tubes 0 ontheir way to the uptake E.

F indicates the casing of the boiler.

Longitudinal or transverse baffle-plates may be provided between thetubes 0, so as to cause the flames and gases of combustion to take acircuitous course on their way to the uptake and chimney, or in lieuthereof the modified arrangement shown in Fig. 3'may be adopted, inwhich the tubes of the middle and outer rows cross each other at themiddle, so as to obstruct the passage of the flames and gases at thatpart, and thus cause them to take the circuitous course indicated by thearrows, firebrick cheeks D being provided at the sides of the furnace toobstruct the direct passage of the flames between the lower ends of theinner rows of tubes. The tubes'G, of larger diameter than the tubes 0,connect the chambers A and B B at the ends of said chambers outside thecasing F for effecting the downward circulation of the water.

In Fig. 4 two upper steam and water chambers A A are shown, constructedsimilar in form to the lower ones B B, to which said chambers A A areconnected by the tubes 0 O in such manner that the two sets of tubescross each other over the furnace, as shown, so that as the part. wherethe tubes cross acts as a battle the flames and hot gases are made toeffectually penetrate first between the lower ends of the tubes and thenbetween the upper ends of the same on their way to the uptake E. The twosets of tubes 0 C may, however, connect the upper chambers A and lowerchambers B without crossing.

From the description above given it will be perceived that I provide twobottom waterchambers at some distance apart with the furmace andflame-space between them, and above these I provide an upper chamber forwater and steam, situated at the apex of a triangle having the two lowerchambers at the extremities of its base. Each of the lower chambers is asemi-cylinder having a flat cover flange-jointed to it, this coverhaving holes through it, so as to constitute a tube-plate, and lying atan angle. I make the upper chamber a cylinderin two parts flange-jointedtogether, and I bore in its lower side two sets of holes for tubescorresponding with thoseof the tubeplates below. Between the upperchamber and each of the lower chambers I fix a number of straight orapproximately straight tubes, which lie at an angle. I secure the tubesin the usual way either by screwing or by expanding their ends in theholes in the tubesheets. By unbolting the flanges and removing thebottom parts of the lower chambers I get access to the lower ends of thetubes,and by removing the upper part of the upper chamber I get accessto the upper ends of the tubes. It will also be perceived that insteadof a single upper chamber receiving both sets of tubes I provide for twoupper chambers flangejointed; the one chamber receiving one set of tubesand the other receiving the other set of tubes, as alreadyhereinbeforedescribed. By making the chamber A a true, cylinder, yet at the-sametime longitudinally and diametrically divided, so that the twosemi-cylinder halves may be separably united by bolts, andcombining'this chamber with the semi-cylinders at the sides of thegrate-bars, said semi-cylinders-being also separably bolted to flattubesheets,-there is secured not only the vital characteristic ofstrength to all parts, but the equally vital feature, in particular forthis class of boilers, mostly of limited size, of accessibility to thetubes for cleaning, repair, or replacement: I v e t i v I am'aware-t'hatmany years ago it was proposed to connect in some indeterminate waywithin a furnace steam and water chambers discharging at one open endinto an interior Water space between water walls of a shell-boiler orpartialshellboiler, and such a construction I do not claim. Suchconstruction is a practically permanent connection and not a separableconnection of any of its parts." Moreover, in so great a mass of wateras must be contained in said water-space exposedto the full heat of thefurnace thetendency of the circulation of the water to therein'ascendand thus defeat the course of circulationdesired is so great thatspecial mechanical means were proposed to produce a descending currentin'the water-space. Great weight of water and of metal, greater complexity and cost, and less durability are also involved in the useofsaid water-space-shell connstruction. In my invention the separablecharacter of each entire generator-chamber into two parts or sections isone of its essential elements. Both parts in all the generatorchambersare not only secured together by steam-tight joints'at both sides, butin both heads also by bolts through said joints. Not only do no ends ofany of my generator-chambers connect with or discharge between shellwater-walls in the .furnace, but both ends of each generator are closedby heads outside of the furnace-walls and no shell constructions areanywhere employed.

Having thus fully described my said invention, I clai'n r l.- In awater-tube boiler for the generation of high steam, the combination ofthe-following named elements: generator chambers, each chamber composedof two sections separably secured togetherlongitudinallyon both sidesand both heads by bolts passingthrough steam-tight joints in said sidesand heads, water-tubes for ascending circulation within a f nrnace andconnecting one section of .eachof said chambers to a sectionofanotherchamher, and downcast pipes outside of the furnace-walls,connecting said generator-chambers, substantially as and for thepurposes set forth. v 2. In a water-tube boiler, the combination of asingle upper generator cylinder or drum composed of two semicylindersseparably bolted together longitudinally through steamtightjoints in both sides and heads and lower water-chambers composed each oftwo sections, the one a flat tube-sheet and the other a semi-cylinder,separably bolted togetherlongitudinally through steam-tight joints inboth sides and both ends, said upper cylinder and lower chambers beingconnected by circulating-tubes within the furnace, whereby access isobtained to both ends of said tubes by the removal of the bolts in saidjoints, substantially as set forth.

A. F. YARROW.

Witnesses:

ANN UNDERwoon, EMILY J. PEASCOD.

